Stainless Steel PH13-8Mo | UNS S13800

PH Stainless Steel PH13-8Mo | UNS S13800 | XM-13

PH13-8Mo is a premium precipitation-hardening stainless steel developed to provide a superior combination of strength, toughness, weldability, and corrosion resistance. The alloy derives its high mechanical properties from a martensitic matrix strengthened by finely dispersed precipitates formed during aging treatment.

Compared with conventional stainless steels and many PH grades, PH13-8Mo offers excellent transverse toughness, reduced segregation, and improved mechanical property consistency, making it highly desirable for aerospace and critical engineering applications.

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PH13-8Mo At a Glance

Key Attribute	Value
Material	PH13-8Mo Stainless Steel
UNS Number	S13800
Common Name	XM-13 / 13-8 PH
Material Type	Precipitation Hardening Stainless Steel
Structure	Martensitic PH Stainless Steel
Density	7.76 g/cm³
Main Strengthening Method	Precipitation Hardening
Tensile Strength	Up to 1,550 MPa
Main Advantage	Ultra-High Strength & Toughness
Typical Industries	Aerospace, Nuclear, Defense, Energy

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Features of PH13-8Mo

• Exceptional strength-to-weight ratio
• Excellent fracture toughness
• Superior transverse toughness
• Outstanding stress corrosion cracking resistance
• Excellent fatigue resistance
• Good weldability
• Uniform mechanical properties
• High hardness capability after aging
• Good corrosion resistance in industrial environments
• Excellent dimensional stability during heat treatment

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Chemical Composition of PH13-8Mo

Element	Content (%)
Chromium (Cr)	12.25 – 13.25
Nickel (Ni)	7.50 – 8.50
Molybdenum (Mo)	2.00 – 2.50
Aluminum (Al)	0.90 – 1.35
Manganese (Mn)	≤ 0.10
Silicon (Si)	≤ 0.10
Carbon (C)	≤ 0.05
Phosphorus (P)	≤ 0.01
Sulfur (S)	≤ 0.008
Iron (Fe)	Balance

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Physical Properties of PH13-8Mo

Property	Value
Density	7.76 g/cm³
Melting Range	1404 – 1454°C
Electrical Resistivity	0.80 μΩ·m
Thermal Conductivity	18.6 W/m·K
Specific Heat Capacity	460 J/kg·K
Modulus of Elasticity	196 GPa

PH13-8Mo Heat Treatment and Condition Selection

PH13-8Mo is often selected where high strength, toughness and controlled aerospace documentation matter. Heat treatment condition should be confirmed against AMS, ASTM or project requirements before quotation and production.

Condition	Typical Selection Reason	RFQ Detail
Solution treated	Machining or preparation before aging	Confirm final aging route and whether machining occurs before heat treatment.
H950	High strength for aerospace and precision components	Confirm tensile, yield, hardness and fracture/toughness requirements if specified.
H1000 / H1050	Balanced strength and toughness	Commonly reviewed where toughness and corrosion resistance are important.
H1150	Lower strength with improved toughness	Confirm service environment, stress level and project acceptance criteria.

Mechanical Properties of PH13-8Mo

Aged Condition Typical Values

Property	Typical Value
Tensile Strength	1,350 – 1,550 MPa
Yield Strength (0.2%)	1,200 – 1,450 MPa
Elongation	10 – 15%
Hardness	38 – 45 HRC

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Corrosion Resistance

PH13-8Mo provides corrosion resistance superior to many high-strength alloy steels and comparable to 17-4PH in many environments.

It offers:

• Good atmospheric corrosion resistance
• Good marine atmosphere resistance
• Excellent stress corrosion cracking resistance
• Good resistance to industrial chemicals
• Improved resistance to hydrogen embrittlement
• Excellent corrosion-fatigue performance

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High Temperature Performance

PH13-8Mo is primarily designed for high-strength structural applications rather than prolonged elevated-temperature exposure.

Recommended Service Temperature

• Cryogenic temperatures
• Ambient temperatures
• Up to approximately 315°C (600°F)

Above this range, over-aging may reduce strength.

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PH13-8Mo Bar and Forging Supplier Notes

PH13-8Mo inquiries are often bar, forged bar, ring, plate or machined component requirements. Include AMS 5629 or project standard, diameter or drawing, heat treatment condition, machining allowance, UT class, mechanical property requirements, MTC type and destination country.

Available Forms

J&A Alloy supplies PH13-8Mo in:

• Round Bar
• Forged Bar
• Plate
• Sheet
• Billet
• Block
• Ring Forgings
• Wire
• Tube
• Custom Machined Parts

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Applications of PH13-8Mo

Aerospace

• Aircraft structural components
• Landing gear components
• Fasteners
• Engine hardware

Defense

• Missile components
• Weapon systems
• Armor support structures

Energy

• Nuclear reactor components
• High-pressure equipment

Industrial

• Valve stems
• Pump shafts
• Tooling components

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PH13-8Mo vs Other PH Stainless Steels

Grade	Strength	Toughness	Main Advantage
PH13-8Mo	Excellent	Excellent	Best Strength/Toughness Balance
17-4PH	Very Good	Good	General Purpose PH Grade
15-5PH	Very Good	Very Good	Aerospace Applications
A286	High	Good	Higher Temperature Capability

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Welding & Fabrication

Welding

Recommended processes:

• GTAW (TIG)
• GMAW (MIG)
• Resistance Welding
• Laser Welding

Heat Treatment

Solution Treatment:
927 – 954°C

Air Cool

Age Hardening:
510 – 593°C

Machining

PH13-8Mo machines well in the solution-treated condition and develops maximum strength after aging.

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PH13-8Mo vs 17-4PH vs 15-5PH

PH13-8Mo is usually considered for higher-end aerospace or critical high-toughness components. 15-5PH is often selected where improved toughness over 17-4PH is desired. 17-4PH remains the common general-purpose PH stainless grade for shafts, valves and fasteners. Related pages: Super Stainless Steel Products, Aerospace Alloys and 17-4PH Bar Supplier.

Standards & Equivalent Grades

Standard	Designation
UNS	S13800
AISI	XM-13
Common Name	13-8 PH
AMS	5629
ASTM Bar	A564 Type XM-13
ASTM Plate	A693 XM-13

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Frequently Asked Questions

What is PH13-8Mo stainless steel?

PH13-8Mo is a martensitic precipitation-hardening stainless steel known for exceptional strength, toughness, and corrosion resistance.

What is the UNS designation of PH13-8Mo?

UNS S13800.

Is PH13-8Mo stronger than 17-4PH?

Yes. PH13-8Mo generally provides higher toughness and higher achievable strength levels.

What is XM-13 stainless steel?

XM-13 is the AISI designation for PH13-8Mo stainless steel.

Can PH13-8Mo be welded?

Yes. It has excellent weldability and is commonly welded in aerospace applications.

What industries use PH13-8Mo?

Aerospace, defense, nuclear, energy, and high-performance engineering industries.

Is PH13-8Mo corrosion resistant?

Yes. It offers excellent resistance to atmospheric corrosion and stress corrosion cracking.

What forms are available?

Bar, plate, sheet, forgings, wire, rings, billets, and machined components.

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Why Choose J&A Alloy

PH Stainless Steel Expertise

Specialized supplier of precipitation-hardening stainless steels and aerospace alloys.

Comprehensive Quality Control

• PMI Testing
• Chemical Analysis
• Mechanical Testing
• Hardness Testing
• Ultrasonic Inspection

International Standards Compliance

• AMS Standards
• ASTM Standards
• EN 10204 3.1 Certification
• Third-Party Inspection Available

Advanced Processing Services

• Precision Machining
• Forging
• Heat Treatment
• Custom Manufacturing

Global Aerospace Supply Experience

Trusted supplier for aerospace, defense, nuclear, and industrial engineering sectors worldwide.